CardioExchange Archive

In the latest development in its ongoing review of the new oral anticoagulant dabigatran (Pradaxa, Boehringer Ingelheim), the FDA today offered largely reassuring news about the sometimes controversial drug. The FDA study of over 134,000 Medicare patients found that dabigatran was associated with a reduced risk for ischemic stroke, bleeding in the brain, and death, compared with warfarin. But the study also found that dabigatran was associated with an increased risk for major gastrointestinal bleeding. There was no difference between the drugs in the risk for MI.

The FDA said the new study was “based on a much larger and older patient population than those used in FDA’s earlier review of post-market data, and employed a more sophisticated analytical method to capture and analyze the events of concern.” The findings were mostly consistent with earlier results from the pivotal RE-LY study, although an increased risk for MI found in the earlier study was not found in the new FDA study.

The FDA said that it will publish the Medicare study in the future and that it will continue to “to investigate the reasons for differences in major GI bleeding rates for Pradaxa and warfarin observed” in this study and in a previous study.

The FDA said it has not made any changes to the label for dabigatran and that it continues to believe that dabigatran has “a favorable benefit to risk profile.” The agency said that patients should not stop taking dabigatran or warfarin without first consulting with their physician.

Since its approval in 2010, dabigatran has been the subject of numerous safety questions and inquiries. According to IMS figures cited by the FDA, U.S. outpatient retail pharmacies have dispensed about 6.2 million prescriptions of dabigatran for 934,000 patients since 2010.

Here are the main findings of the FDA study:

Table 1. Incidence rates and adjusted hazard ratios comparing matched new user cohorts treated with Pradaxa 75 mg or 150 mg* or warfarin for non-valvular atrial fibrillation based on 2010-2012 Medicare data. Warfarin is the reference group.

* Primary findings for Pradaxa are based on analysis of both 75 and 150 mg together without stratification by dose.